An improved container designed to provide all of the foregoing attributes (including light weight, low cost, ease of use and carrying, and climatic tolerance) while also presenting a virtually impenetrable barrier to animals. One exemplary embodiment comprises a highly resilient, lightweight, one piece polymer (polycarbonate) body or shell having a large-diameter aperture disposed at one end. A threaded, partially flexible lightweight polymer cap element mates with the body; the cap element comprises a tamper-resistant configuration with locking features which prevent rotation of the cap with respect to the body past a certain point. A ridge is formed on the body along the mating region of the cap, the ridge acting to prevent any animal (or human for that matter) from being able to insert anything (e.g., claws) under the cap when installed to pry it off. The locking features, ridge, body, and cap coordinate to make the container pliable enough to distort without opening, yet resilient and rugged enough to prevent permanent deformation, fracture, or cracking even under the weight (and motive forces) of a fully grown bear.